There are a variety of ways to interact with electronic devices. For example, hardware such as keyboards and mice are often used to provide input to a computer. Smartphone and tablets typically have several mechanical buttons that trigger particular functions. Additionally, modern smartphones and tablets often include touch sensitive screens. Users can interact with the devices by tapping or swiping across the screen.
Technologies have been developed to allow a user to interact with a device without touching it. For example, the Microsoft Kinect® is a device that includes an optical sensor. A user can control a television by standing in front of the optical sensor. For example, the user can wave his or her hand to move to another section of a user interface. There are continuing efforts to develop still other ways of interacting with electronic devices.